( 334 ) 
clearly that it is quite well possible that the dried part at the apex 
might divide itself into two concentric portions; the inner member 
of which, wearing chiefly the stamens, would belong to the central 
body of the apple and the circular exterior to the envelope. On a 
nearer inspection of the different portions of the described apple it 
is evident that such has undoubtedly been the case here, and it is, 
moreover, to be observed in the figure. At the top of the envelope 
there are only fragments which remind of the calyx, whilst, the 
top of the inner apple wears, besides a few remnants of the calyx, 
the whole circle of dried stamens. 
How the fungus has entered the apple; from whence the growth 
of the mycelium has begun; when the severing of the two parts 
has taken place, — these are questions not to be answered with 
the help of this one object. But the case appeared to me remark- 
able enough to describe it in short, whilst it will be of importance 
henceforth in the appearance of similar monstrosities, to pay atten- 
tion to the presence of fungi. 
Chemistry. — “On the Theory of the Transition Cell of the third 
kind’. By Dr. Ernst Conen. (First part.) (Communicated 
by Prof. H. W. Baknurs RoozeBoom.) 
1. The theory of the transition cell of the third kind, to which 
VAN ’r Horr!) first drew attention, has not yet been considered. 
In a former paper*) I have pointed out that it may be verified 
by means of JAEGER’s *) measurements, but that a number of expe- 
rimental data needed for the complete calculation are still lacking. 
In what follows I propose to develop in the first place the thermo- 
dynamic theory of these elements, then to describe the experiments 
which have been made for the determination of the quantities re- 
quired in the calculations, whilst, finally, the results of theory and 
experiment will be compared with one another. 
1) van °r Horr, Vorlesungen über die Bildung und Spaltung von Doppelsalzen, 
Leipzig (1897), S. 29. Also: Vorlesungen über theoretische und physikalische Chemie, 
Erstes Heft. 5. 179. — Ernst Conen, Ueber eine neue (vierte) Art Umwandlungs- 
elemente, Zeitschr. fiir phys. Chemie, 25 (1898) 300. 
2) Zeitschrift für phys. Chemie 25 (1898), 300. — Maandblad voor Natuurweten- 
schappen, 22 (1898) 17. 
3) WiepeMann’s Annalen, Bd. 63 (Jubelband) (1897) 354. 
